Sheet guiding apparatus



1955 G. B. WOOD, JR 2,722,415

SHEET GUIDING APPARATUS Filed Oct. 25, 1950 3 Sheets-Sheet 1 Nov. 1, 1955 Filed Oct. 25, 1950 G. B. WOOD, JR

SHEET GUIDING APPARATUS 3 Sheets-Sheet 2 NOV. 1, 1955 WOOD, JR- 2,722,415

SHEET GUIDING APPARATUS Filed Oct. 25, 1950 3 Sheets-Sheet 3 Z I, I 3 /jJZ 160 f i Ifio INVENTOR. 1 1 Zmvofl/ 1 MAW 126 1 H1 6f 11% 1 z United States Patent 2,722,415 snanr GUIDING APPARATUS George B. Wood, Jr., Bridgewater, Mass., assignor to John Douglas Robertson, Taunton, Mass.

Application ()ctober 25, 1950, Serial No. 191,989 13 Claims. (Cl. 271-2.6)

This invention relates to improvements in apparatus for guiding travelling sheet material in a predetermined path. More particularly it relates to sheet guiding apparatus which, when required, moves a travelling sheet into its predetermined path by a relatively quick lateral bodily shift of the sheet or web, as compared with prior comparable guiding procedures in which any lateral shifting of a travelling sheet has involved a gradual lateral crawling of the sheet along an engaged roll or rolls.

When sheet materials, such as cloth, paper, foils, plastic film, and the like, are travelling to a processing device, such as a tenter frame or other mechanism which is to perform some function on the sheet, it usually is important to have the sheet approach the processing device or mechanism in a predetermined proper path. Various sheet guiding devices have been available heretofore designed to bring a travelling sheet into its proper path, and to maintain it against any substantial departure from that path. However, all of the prior devices, so far as I am aware, accomplish lateral shifting of a travelling sheet by causing the sheet, or a marginal portion thereof, to crawl along one or more tilted rolls engaging the sheet.

These prior methods of guiding inevitably involve a delay between the time when the rolls are tilted and the time when the correction is accomplished. A small correction will involve a short delay, a large correction a longer delay. Because of the delay, the sheet being acted upon becomes shifted beyond its proper position. If the roll tilting mechanism is made active enough to provide a reasonably quick guiding effect, the net result is that the sheet tends to float back and forth with the sheet edges moving first a little to one side of their proper paths and then a little to the other side of their proper paths.

It is among the objects of my present invention to provide sheet guiding apparatus which is operative to quickly shift a travelling sheet laterally into its proper path without any appreciable time delay between detection of an out-of-proper-path condition and the correction of the detected condition. According to the invention, the sheet is carried bodily into its proper path, without any need for the sheet to gradually crawl into its proper path, thus avoiding the time delay heretofore involved before the correction could be attained.

Another object of the invention is to provide sheet guiding apparatus which is operative to quickly shift a travelling sheet laterally into its proper path without any appreciable time delay between detection of an out-ofproper-path condition and the correction of the detected condition, and simultaneously operable to counteract any prevailing tendency of the sheet to move back out of its proper path. My improved sheet guiding apparatus carries the sheet bodily into its proper path and simultaneously tilts an engaged roll or rolls in direction and amount whereby the tilt of the roll is effective to maintain the sheet in its proper path in opposition to forces which may be operative tending to move the sheet out of its proper path.

A feature of the invention resides in elimination of the heretofore prevalent oscillating of a sheet, back and forth between feeler fingers at opposite sides of the proper path of the sheet. According to the invention, the sheet is carried into its proper path with no need to carry it beyond the proper path, and the sheet continues to travel substantially in its proper path, with a minimum of departure therefrom, because the roll or rolls with which the sheet is engaged become tilted and conditioned automatically for counteracting prevailing forces which may be tending to displace the sheet laterally out of its proper path.

A. further object of the invention is to provide sheet guiding apparatus which is operative to quickly shift a travelling sheet into a predetermined path, and to maintain it there, in response to actuations of a selvage feeler finger, or comparable detector means. According to the invention, this fceier finger or other detector means effectively responds to lateral movements of the sheet in either direction, to quickly effect restoration of the sheet to its proper path.

It is, moreover, my purpose and object generally to improve the structure and effectivenes of sheet guiding devices and mechanisms, and especially to improve such devices and mechanisms wherein the guiding is effected by operation of a tilting roll or rolls, or the like, in response to detector means coacting with one or both edges of the travelling sheet.

In the accompanying drawings:

Fig. l is a diagrammatic plan View of sheet guiding apparatus embodying features of the invention, showing a pivoted roll-carrying frame in a dot and dash position in which it is engaged by an out-of-proper-path sheet which is shown by dotted lines, and showing the frame and sheet in full lines in their positions following correction of the path of travel of the sheet;

Fig. 2 is a medial longitudinal cross-sectional view of the apparatus and sheet of Fig. 1, including the support for the roll-carrying frame and means for moving the frame about its pivot;

Fig. 2a is a fragmentary cross-sectional view of one end of a modified form of frame arm, supporting one end of each of two spaced and parallel rolls in associated relation;

Fig. 3 is a wiring diagram illustrating electrical control circuits which may be employed foroperating the rollcarrying frame of Figs. 1 and 2;

Fig. 4 is a plan view of a modified form of support and operating means for a correcting roll similar to' that of Figs. 1 and 2;

Fig. 4a is a diagrammatic representation of fluid pressure mechanism which may be employed for shifting the positions of the correcting roll of Fig. 4, in response to actuations of a detecting finger, or the like;

Fig. 5 is a plan view of another modified form of sheet guiding apparatus embodying features of the invention, the correction roll being of a curved expansion roll t e;

lig. 6 is a medial longitudinal cross-sectional view of the apparatus and sheet of Fig. 5; and

Fig. 7 is a plan view of still another modification of sheet guiding mechanism embodying features of the invention, with portions broken away.

Referring to the drawings, the sheet 10 is representative of flexible sheets in general, travelling in the direction of the arrows toward a device 12 which may be any of various conventional devices or mechanisms for performing some operation on the sheet. In Figs. 1 and 2, the sheet 10 may be coming from any suitable supply source, not shown, engaging the under side of the fixed guide roll 14 and passing thence in engagement with the upper side of a movable roll 16, whence it continues on its course into engagement with a second fixed guide roll 18 and on into the processing device or mechanism 12,

3 which may be a tenter frame, for example, if the sheet is a web of cloth.

According to the inventIon, the movable roll 16 is mounted for rotation in a frame having the generally V-shape as best seen in Fig. 1. The roll is journalled at its opposite ends in the ends of the arms 20', 20" of the V-frame 20, and the V-frarne is pivotally mounted at 22 for rotation on an axis perpendicular to the general plane of travel of the sheet 10. The axis of rotation of the V-frame is located approximately on the centerline of the predetermined proper path of the sheet at the approach to the processing device 12, and the arms of the V-frame extend from the pivotal axis at 22 generally in direction toward the processing device 12 but with appreciable inclination upwardly toward sheet 10, as well as outwardly in generally opposite directions. The ends of arms 20, 20" of the V-frame are spaced apart a distance for accommodating a roll 16 having iength substantially longer than the width of the stheet 10, and the guide rolls 14, 18 also will have lengths substantially greater than the width of sheet 10.

Fig. 1 illustrates, more or less diagrammatically, a condition in which the sheet 10, for one reason or another, would come to the processing device 12 on a natural course not aligned with the center-line of the device 12. This misaligned course of sheet 10 is shown by the dotted representation of the sheet at 1.0 in Fig. l, and the pivoted frame 20 is represented by dot and dash lines in its neutral position prior to correction of the path of travel of the sheet at the approach to the processing device 12.

The full line representation of sheet 10 in Fig. 1 shows it after the frame 20 has been swung clockwise about its pivot to its position in which its exposed parts are shown in full lines, the portion of the sheet between roll 16 and the processing device 12 being shifted by roll 16 into its predetermined proper path.

Swinging of frame 20 may be accomplished by any suitable mechanism, in response to any suitable detecting means arranged and adapted to effect movement of frame 20 in proper sheet-path-correcting direction Whenever an edge portion of the sheet is detected as being out of its predetermined proper path. Fig. 2 shows the frame fixed to the upper end of a pivot shaft 22 which is journalled in a suitable fixed bearing support 26. The lower end of pivot shaft 22 has a gear 28 fixed thereon and gear 28 meshes with a pinion 30 on the shaft of a reversible electric motor 32 which may be mounted on the fixed support 34. Operation of the motor in one direction causes the frame 20 to swing clockwise about I its pivotal axis, and operation of the motor in the opposite direction causes frame 20 to swing counter-clockwise about its pivotal axis.

The detecting means may be a well known type of photo-electric device wherein a beam of light is interrupted by the travelling sheet so long as the sheet is in its predetermined proper path, but strikes and activates a photo-electric cell whenever the sheet departs laterally out of its proper path. Motor 32 may be responsive to activation of the photo-electric cell, in a well known manner, to quickly restore the sheet to its proper path. However, for illustrative purposes, the detecting means as herein shown comprises a single detector element or finger 24 which is located adjacent to the predetermined proper path of one edge of the travelling sheet 10.

The wiring diagram of Fig. 3 shows one way in which the motor 32 may be operated in either direction in response to actuation of detector finger 24. The finger is pivoted at 36 and extends upward in position to be engaged by the adjacent edge of sheet 10. Also, it has a depending projection 24 which is engaged by a spring 38 which constantly biases the finger 24 clockwise about its pivot 36. The finger 24 constitutes a movable contact of a switch which includes the fixed contacts 40, 42

spaced apart on opposite sides of the finger. When the sheet 10 is travelling in its proper path by the detector finger 24, the finger is held by the sheet 10 in its neutral position of Fig. 3, out of contact with both of the fixed contacts 40, 42. A departure of sheet 10 to the right in Fig. 3 will permit the finger to swing into engagement with fixed contact 42, under the bias of spring 38. A departure of sheet 10 to the left in Fig. 3 will swing the finger, in opposition to the bias of spring 33, into engagement with fixed contact 40.

A three-phase motor circuit is represented at 44 in Fig. 3, and includes the normally open switches indicated generally at 46, 48. A solenoid is operative, when energized, to close the motor circuit switch 46 thereby to condition motor 32 for operation in one direction. A similar solenoid 52 is operative, when energized, to close the motor circuit switch 48 thereby to condition motor 32 for operation in the opposite direction.

Solenoid 50 becomes energized when selector finger 24 engages fixed contact 40, and solenoid 52 becomes energized when selector finger 24 engages fixed contact 42. The motor circuit may be a 220 volt circuit, While the control circuit preferably will be supplied with low voltage current from the low side of the transformer 54.

Motor 32 may be equipped with a well known type of mechanism for quickly stopping its rotor when current to the motor is cut off by opening of a switch 46 or 48. A contact member 56 is loose on the motor shaft so that friction tends to rotate member 56 in whichever direction the motor shaft is rotating. Two pairs of contacts 58, are located on opposite sides of contact member 56, the contacts 58 being in position to be bridged by member 56 when the latter is rotated clockwise in Fig. 3, and the contacts 60 being in position to be bridged by member 56 when the latter is rotated counter-clockwise in Fig. 3. Assuming that sheet 10 shifts to the right in Fig. 3 enough to permit finger 24 to engage contact 42, energization of solenoid 52 will occur and cause closing of motor circuit switch 48, starting the motor operating clockwise in Fig. 3. This clockwise rotation of the motor shaft causes the contact member 56 to rotate into bridging engagement with contacts 58, thereby conditioning a low voltage circuit for energizing the solenoid 50 as soon as the motor circuit switch 48 opens. Hence, as soon as the motor circuit which was driving the motor clockwise opens, the solenoid 50 becomes energized to close motor circuit switch 46 to complete the circuit for driving the motor counterclockwise. However, the initial rotation of the motor shaft in counter-clockwise direction carries contact member 56 out of bridging relation to contacts 58 to deenergize solenoid 50 with resulting opening of motor circuit switch 46 while the contact member 56 is out of contact with both pairs of contacts 58, 60. This socalled plugging or braking of the motor effectively avoids any appreciable over-running of its rotor. A similar momentary reversal of direction of the motor results following a counter-clockwise operation of the motor, the contacts 60 being bridged in this case with subsequent energizing of solenoid 52 when motor circuit switch 46 opens.

It is a feature of the invention that when the sheet 10 is bodily shifted into its proper path, as from its dotted position to its full line position in Fig. 1, there is no substantial delay involved from the time the detector finger 24 calls for a shift of the sheet until the actual accomplishment of the proper amount of shift. Perhaps more important, however, is the fact that, in accomplishing the shift of the sheet 10 into its proper path, the roll 16 becomes simultaneously tilted in the general plane of travel of the sheet, more or less, depending upon the magnitude of the required correction. If, to correct a misalignment of the sheet, it were shifted by merely moving the roll 16 endwise, the sheet would crawl back toward its original misaligned path. However, under a condition as presented in Fig. 1, the endwise movement of the roll 16 bodily shifts the sheet into its proper path and the simultaneous tilting of the roll 16 tends to keep the sheet in its proper path. If the tilt is not correct after the initial swing of the frame and roll, the sheet will crawl toward a new misaligned path. This will initiate a second and smaller shift of the roll, eliminating or reducing further the tendency of the sheet to crawl out of alignment. If the axis of pivot 22 intersects the axis of lead on roll 14, the relatively large arc of swinging of the roll ordinarily will permit a misalignment of the sheet to be corrected by a single swing of the roll. If these axes are relatively far apart, with pivot 22 closer to the roll, two or more successively smaller swings may be required before the machine settles down, due to the smaller arc of swinging of the roll. These successively smaller swings should not be confused with the continual oscillation characteristic of the prior guiding devices. That characteristic oscillaton in the prior devices is caused by the inherent delay and the subsequent over-correction. My new guider, as herein disclosed, avoids the continuing oscillation by avoiding the delay. In the Figs. 1 and 2 embodiment, the pivot 22 is shown spaced from roll 16 a distance substantially greater than the width of the sheet 10. Its spacing from roll 16 should not be substantially less than the width of the sheet which is being handled, nor substantially greater than one and one-half times the width of the sheet 10 being handled.

Figs. 1 and 2 show a simple single roll embodiment of the invention. It presently is considered preferable to employ a pair of rolls on the pivoted frame 20, as illustrated in Fig. 2a, with the sheet 10 passing under one roll, such as roll 16, and over the other roll, such as roll 17. As compared with the single roll embodiment, this provides substantially greater surface engagement of the rolls by the sheet 10, with resulting increased resistance to slipping of the sheet along the engaged rolls.

The embodiment of the invention illustrated in Fig. 4 acts on sheet 10 generally in the same manner as the embodiment of Figs. 1 and 2. In Fig. 4, a pair of links 62 support the roll 16, or may support two rolls associated as in Fig. 2a. The links 62 are inclined toward each other with their outer ends pivotally connected at 64 to any suitable fixed support 66. A bearing member 68 is pivotally connected to the free end of each link, for journalling the opposite ends of roll 16. When either link is swung in either direction about its pivot, the other link swings in the same direction about its pivot. However, because of the inclinations of the links, any such swinging of the links from their neutral positions of Fig. 4, causes the roll 16 to tilt simultaneously with its lateral movement.

Swinging of the link 62 in Fig. 4 may be accomplished by any suitable means in response to actuations of a de tector finger 24, such as by the motor-driven worm gear 70 to which an actuating rod 72 is eccentrically connected at 74. The other end of rod 72 is pivotally connected to one of the links 62. The motor may be a reversible motor as described in connection with the Pigs. l-3 embodiment, with electrical control means as diagrammatically represented in Fig. 3. The motor shaft is shown in Fig. 4 equipped with a worm 76 in mesh with the worm gear 70.

Fig. 4a illustrates diagrammatically how the roll-carrying links 62 of the Fig. 4 embodiment may be swung hydraulically, or by other fluid pressure. A cylinder 78 is pivotally connected at one end to a suitable fixed support 80, with a piston 82 operable in the cylinder. A

piston rod 84 extends out of the free end of the cylinder and is pivotally connected to one of the links 62. Opposite end portions of the cylinder 78 are connected by conduits 86, 88 to a valve casing 90. A slide-valve 92 6 Within casing is normally held in its illustrated neutral position by the similar springs 94, 94 at opposite ends of the valve casing.

Fluid under pressure from any suitable source is conducted to the valve casing through supply conduit 96 which has the spaced delivery end portions 96, 9 at the casing 90. The conduits 86, 88 from cylinder 78 open into the valve casing opposite the supply conduit portions 96 and 96 respectively. A transverse flow passage 98 through the valve 92 stands centrally between the conduits 86, 88 when the valve is in its neutral position as shown in Fig. 4a.

Two exhaust ports 100, 102 in valve 92 are located on opposite sides of the valve flow passage 98, the port 180 being adapted to register with conduit 86 and exhaust conduit 104 when the valve is moved a predetermined amount downwardly in Fig. 4a, and the port 102 being adapted to register with conduit 88 and exhaust conduit 106 when the valve is moved a predetermined amount upwardly in Fig. 4a. A said predetermined downward movement of the valve brings the flow passage 98 into register with conduit 88 and conduit portion 96", whereby pressure fluid delivers into cylinder 78 at the under side of piston 82, while the cylinder at the upper side of the piston, is open to exhaust through conduit 86, valve port 160 and exhaust conduit 104. A said predetermined upward movement of the valve 92 brings the flow passage 98 into register with conduit 86 and conduit portion 96', whereby pressure fluid delivers into cylinder 78 at the upper side of piston 82, while the cylinder, at the under side of the piston, is open to exhaust through conduit 88, valve port 102 and exhaust conduit 1G6.

Valve 92 may be moved by any suitable means, in response to actuations of the detector finger 24, the particular means shown in Fig. 4a being diagrammatically represented as two oppositely disposed solenoids 188, 110. The valve has a metallic element 112 projecting slidably through each end wall of the valve casing 98, whereby the valve is drawn in one direction when solenoid 108 is energized, and is drawn in the opposite direction when solenoid 110 is energized. Springs 94 act to maintain the valve in its illustrated neutral position when both of the solenoids are de-energized. The detector finger 24 may be the same as described in connection with Fig. 3, with spring 38 constantly biasing it toward engagement with contact 42, and with the sheet 10, when in its proper path, maintaining finger 24 in an intermediate position between contact 42 and a contact 40. When finger 24 is actuated into engagement with contact 40, the solenoid 108 becomes energized, and when finger 24is actuated into engagement with contact 42, the solenoid 110 becomes energized.

Figs. 5 and 6 illustrate an embodiment of the invention wherein the travelling sheet 10 passes around the under sides of guide rolls 14, 18 and over the curved roll 114, which may be an expander roll of the general type having a flexible surface sleeve 116 mounted for rotation about a curved axle 118 whose opposite ends may be suitably mounted in the uprights 120 of a member 122 which is pivotally mounted at 124 on a carriage 126. Carriage 126 is slidably mounted on guide bar 128 which extends transversely of the direction of travel of sheet 10, with its opposite ends connected to the similar frame members 130, 130, which are additionally held in rigid parallelism by the cross bar 132.

Two similar but oppositely disposed cam plates 134, 136 are rigidly mounted on the frame members 130, 130, with additional support on a cross-member 138, and each end portion of the pivoted member 122 has a roller 14-0 mounted thereon engaging respectively the inclined surface of cam plate 134 and the inclined surface of cam plate 136. The arrangement and inclination of the cam surfaces are such that any lateral movement of carriage 126 results in tilting of roll 114 in one direction or the other depending upon the direction of movement of the carriage. As best seen in Fig. 6, the carriage 126, adjacent to pivot 124 is equipped with a roller 142 which rides on transverse track 144.

It will be apparent from Fig. 5 that any lateral movement of carriage 126 will be accompanied by tilting of roll 114 about the pivot 124 of pivoted member 122. The carriage may be moved laterally by any suitable means, in response to actuations of a detector finger 24' comparable to the finger 24 of the previously described embodiments. Conveniently, the finger 24' may be pivoted on the cross bar 132, in position to be engaged by a selvage of sheet 10. Fixed contacts 40', 42 may be mounted on cross bar 132, on opposite sides of finger 24, and a spring, similar to spring 38 in Fig. 3, constantly biases the finger toward contact 42', with the sheet 10, when in its proper path, maintaining the finger at an intermediate location between the contacts 40, 42'. Actuations of finger 24' may control mechanical or fluid pressure means for moving the carriage. As represented in.

Fig. 5, a cylinder 78 has its piston rod 8' connected to the carriage and has conduits 86', 88' for conducting fluid to and from a valve casing (not shown) which may be similar to the valve casing 90 of Fig. 4a, with its valve controlled by actuations of finger 24 the same as the control in Fig. 4a by finger 24.

In addition to the described lateral and tilting movements of roll 114, in response to actuations of detector finger 24, in Figs. 5 and 6, it is desirable to provide for adjustment of the roll 114 about the axis of its end bearings, thereby to vary the expanding effect of the roll on the travelling sheet or, under particular conditions, to provide for lateral contraction of the sheet, under variable control. As shown in Figs. 5 and 6, one end of the curved roll axle 118 has fixed thereon a gear 146 in mesh with a pinion 148 on the shaft of a reversible electric motor 32 which may be similar to motor 32 of the Figs. 1-3 embodiment, and which may be controlled in the manner described in connection with Fig. 3, in response to actuations of a detector finger 24" coacting with fixed contacts 40", 42" on cross bar 132. While finger 24' responds to lateral departures of one selvage of sheet 10, for controlling movements of carriage 126, finger 24 responds to departures of the other selvage for controlling motor 32 for varying the expansion or contraction effect of roll 114 on sheet 10.

Fig. 7 illustrates a sheet guiding apparatus which is generally similar to the Figs. 5 and 6 embodiment, but showing a straight roll 114 mounted on the pivoted member 122' which is pivoted at 124 on the carriage 126.

The carriage may be moved laterally along the guide 128 f the same as in the Figs. 5 and 6 form. However, tilting of roll 114' is accomplished independently of the lateral movements of carriage 126, by any suitable means, in response to actuations of a detector finger 150 pivotally mounted on the cross bar 132. The finger 150 is con w stantly biased by spring 151 into engagement with the roller 142 on carriage 126 and stands at an intermediate position between fixed contacts 152, 154 when the carriage is in its neutral position as shown. If the carriage moves laterally, in response to actuations of finger 24 or 24" (Fig. 5) enough to permit finger 150 to engage contact 152 or 154, the resulting completed electric circuit operates for tilting the roll 114 in one direction or the other depending on the direction of lateral movement of the carriage. As shown in Fig. 7, a cylinder 156 is pivotally mounted on carriage 126, with its piston rod 158 connected to pivoted member 122' to one side of its pivot 124. Conduits 160, 162 lead from the opposite ends of cylinder 156 and may lead to a valve casing similar to the valve casing 90 of Fig. 4a, whose valve may be controlled by solenoids, as in Fig. 4a, in response to actuations of the detector finger 150 of Fig. 7. Assuming, for example, that a selvage finger 24 or 24", similar to that shown in Figs. 5 and 6, calls for a lateral shift of the roll 114' of Fig. 7, the appropriate terminal or contact 152 or 154 will be contacted by finger 150 to close a circuit for energizing the appropriate solenoid for effecting a tilting of roll 114 in direction to further urge the web laterally in the same direction that roll 114 had been shifted laterally. If the lateral shift of the roll combined with the lateral shifting effect of the inclined roll carries the web laterally enough so that the selvage finger moves past its neutral position and contacts the other terminal or contact 152 or 154, the roll-supporting carriage will move back toward its neutral position but the tilt of the roll continues to exert its eifect on the web tending to hold it in its proper path as the carriage moves toward its neutral position. There may be two or more lateral shifts of the roll and two or more adjustments of the tilt of the roll before the machine settles down with the web held in its proper corrected path of travel and with the roll supporting carriage back in or near its neutral position ready for any needed further lateral shifting of the web. The angle of tilt of the roll will continue to increase as long as finger 150 is in contact with one of the contacts 152, 154, and the tilt of the roll produces lateral shifting of the web additional to the lateral shifting which is due to movement of the roll laterally of the direction of web travel. Hence, the web continues its lateral shifting on the tilted roll, after lateral movement of the roll has ceased, until one of the selvage fingers 24' or 24" closes a circuit which effects a lateral shifting of the roll in the opposite direction, and finger 150 moves away from one contact 152 or 154 toward the other of said contacts.

it will be apparent from the foregoing description, in connection with the drawings, that I have provided sheet guiding means whereby a travelling sheet may be quickly carried bodily in lateral direction to bring it into a predetermined proper path without any appreciable time delay between detection of an out-of-proper-path condition and the actual correction of the path of travel of the sheet. Also, the mentioned shifting of a sheet bodily into its proper path may be accompanied by a tilting of a roll or rolls a proper amount and in proper direction to keep the sheet in its proper path. My improved sheet guiding mechanisms make it possible to maintain a sheet substantially constantly in a predetermined path without the heretofore prevalent back and forth oscillations of the sheet between limits on opposite sides of the proper path of an edge or selvage of the sheet. While I have illustrated motor driven and fluid driven mechanisms for effecting lateral shifting and tilting of the correcting roll or rolls, and for varying the expansion and contraction effect on a sheet when the roll is a curved expander type of roll, it should be understood that the particular means employed for moving the correcting roll or rolls may be of various descriptions, controlled in various ways in response to detector fingers of the general sort illustrated, and it is intended that the patent shall cover, by suitable expression in the appended claims, whatever features of patentable novelty exist in the invention disclosed.

I claim as my invention:

1. In a sheet guiding apparatus for acting on a travel ling sheet which is travelling between two spaced elements disposed in general parallelism in a common plane, a roll disposed generally transversely of the direction of travel of the travelling sheet between said elements, a pivotally mounted frame supporting said roll in engagement with the sheet whereby the sheet rotates the roll in said frame, a carriage supporting said pivoted frame and movable transversely of the direction of sheet travel for moving said roll in a plane generally parallel with said common plane of said elements, detector means arranged and adapted to be actuated when the sheet becomes displaced out of its predetermined proper path, means responsive to an actuation of the detector means, and operative independently of forces transmitted to the roll by the travelling sheet, for moving the said carriage transversely of the direction of sheet travel, and means responsive to a said movement of the carriage for swinging said rollcarrying frame about its pivot thereby to swing said roll in said generally parallel plane, whereby the sheet is quickly carried laterally on the roll by the transverse movement of the carriage with portions of the sheet at opposite sides of said roll being carried by the roll toward said predetermined proper path, said swinging of the frame effecting a tilting of the roll in said generally parallel plane in direction and amount to maintain the sheet substantially in its new position.

2. In a sheet guiding apparatus, a roll disposed generally transversely of the direction of travel of a travelling sheet which is to be guided, a pivotally mounted frame supporting said roll in engagement with the sheet whereby the sheet rotates the roll in said frame, a carriage supporting said pivoted frame and movable transversely of the direction of sheet travel, detector means arranged and adapted to be actuated when one edge of the sheet becomes displaced laterally out of its predetermined proper path, a second detector means arranged and adapted to be actuated when the other edge of the sheet becomes displaced laterally out of its predetermined proper path, power means responsive to actuations of one of said detector means for moving said carriage transversely of the direction of sheet travel thereby to quickly carry the sheet on said roll into its said predetermined proper path, means responsive to a said transverse movement of the carriage for swinging said frame about its pivot thereby to counteract the tendency of said sheet to move back out of its predetermined proper path, said roll being longitudinally curved for exerting an effect on the engaged sheet tending to change its width, and power means responsive to actuations of said second detector means for varying the plane of extent of the curved axis of the roll thereby to vary the width-changing efliect of the roll on the engaged sheet.

3. The method of guiding a travelling sheet in a predetermined proper path, comprising guiding a travelling sheet on a course leading between two spaced elements disposed in general parallelism in a common plane engaging the travelling sheet by a rotatably mounted roll disposed generally transversely of the direction of travel of the sheet between said elements, whereby the roll is rotated by the sheet, eifecting any needed change of path of travel of the sheet by bodily moving the roll transversely of the direction of sheet travel in a plane generally parallel with said common plane of said elements thereby to quickly carry the sheet on the roll into its predetermined proper path with portions of the sheet at opposite sides of said roll being carried by the roll toward said predetermined proper path, and counteracting any forces which may be tending to move the sheet back to its original path of travel by independently tilting the roll in said generally parallel plane and in direction and amount whereby the tilted roll acts on the engaged sheet with a surface engagement which tends to move the sheet further in the direction in which it was carried by the said transverse movement of the roll with a force approximating the forces acting on the sheet in the opposite direction, whereby the sheet tends to remain in its said predetermined proper path.

4. The method of quickly moving a travelling sheet laterally into a predetermined path and maintaining it there, comprising guiding a travelling sheet on a course leading between two spaced elements disposed in general parallelism in a common plane, engaging the travelling sheet by a rotatably mounted roll disposed transversely of the direction of sheet'travel between said elements, effecting any needed lateral shifting of the sheet to bring it into its predetermined proper path by moving the roll transversely of the direction of sheet travel in a plane generally parallel with said common plane of said elements thereby to quickly carry the sheet on the roll into its proper path with portions of the sheet at opposite sides of said roll being carried by the roll toward said predetermined proper path, and simultaneously independently tilting the roll in said generally parallel plane to counteract any tendency of the sheet to move back out of its proper path.

5. The method of quickly moving a travelling sheet laterally into a predetermined path and maintaining it there, comprising guiding a travelling sheet on a course leading between two spaced elements disposed in general parallelism in a common plane, engaging the travelling sheet by a rotatably mounted roll disposed transversely of the direction of sheet travel between said elements, effecting any needed lateral shifting of the sheet to bring it into its predetermined proper path by moving the roll transversely of the direction of sheet travel in a curved path in a plane generally parallel with said common plane of said elements with portions of the sheet at opposite sides of said roll being carried by the roll toward said predetermined proper path, the approximate center of the curve being centrally located in the sheet at a point between the source from which the sheet is drawn and said transversely disposed roll and spaced from the roll a distance within the range of approximately one to one and one half times the width of the sheet.

6. The method of quickly moving a travelling sheet laterally into a predetermined path and maintaining it there, comprising guiding a travelling sheet on a course leading between two spaced elements disposed in general parallelism in a common plane, engaging the travelling sheet by a rotatably mounted roll disposed transversely of the direction of sheet travel between said elements, efiecting any needed lateral shifting of the sheet to bring it into its predetermined proper path by moving the roll transversely of the direction of sheet travel in a plane generally parellel with said common plane of said elements, thereby to quickly carry the sheet on the roll into its proper path with portions of the sheet at opposite sides of said roll being carried by the roll toward said predetermined proper path, controlling the said transverse movements of the roll in response to a single detector means at one edge region of the travelling sheet, and independently tilting the roll in said generally parallel plane in response to a said transverse movement thereof to hold the engaged sheet in its proper path.

7. Sheet guiding apparatus for acting on a travelling, sheet which is travelling between two spaced elements disposed in general parallelism in a common plane comprising a roll disposed transversely of the direction of travel of the travelling sheet between said elements, means supporting said roll rotatably in engagement with the sheet whereby the sheet rotates the roll, means operative independently of forces transmitted to the roll by the sheet for moving the roll transversely of the direction of sheet travel in a plane generally parallel with said common plane of said elements thereby to quickly carry the sheet on the roll from an improper path into a proper path with portions of the sheet at opposite sides of said roll being carried by the roll toward said proper path, and means for tilting the roll in said generally parallel plane thereby to hold the sheet in its proper path.

8. Sheet guiding apparatus comprising a roll disposed transversely of the direction of travel of a travelling sheet, means supporting said roll rotatably in engagement with the sheet whereby the sheet rotates the roll, means for moving the roll transversely of the direction of sheet travel thereby to quickly carry the sheet on the roll from an improper path into a proper path with portions of the sheet at opposite sides of said roll being carried by the roll toward said proper path, and cam means arranged to elfect a tilting of the roll in response to said transverse movement of the roll, the said tilting being in direction and amount to produce a force acting on the sheet in opposition to and substantially equal to any forces that may be tending to move the sheet back toward its said improper path.

9. Sheet guiding apparatus for acting on a travelling sheet which is travelling between two spaced elements disposed in general parallelism in a common plane comprising a roll disposed transversely of the direction of travel of the travelling sheet, means supporting said roll rotatably in engagement with the sheet whereby the sheet rotates the roll, means operative independently of forces transmitted to the roll by the sheet for moving the roll transversely of the direction of sheet travel in a plane generally parallel with said common plane of said elements thereby to quickly carry the sheet on the roll from an improper path into a proper path with portions of the sheet at opposite sides of said roll being carried by the roll toward said proper path, detector means responsive to a lateral movement of an edge of said sheet for efiecting a said transverse movement of the roll, and means for tilting the roll in said generally parallel plane in response to a said transverse movement of the roll in said generally parallel plane.

10. Sheet guiding apparatus for acting on a travelling sheet which is travelling between two spaced elements disposed in general parallelism in a common plane comprising a roll disposed transversely of the direction of travel of the travelling sheet, means supporting said roll rotatably in engagement with the sheet, means operative independently of forces transmitted to the roll by the sheet for moving the roll transversely of the direction of sheet travel in a plane generally parallel with said common plane of said elements thereby to carry said sheet, including portions at opposite sides of said roll, generally in the direction of transverse movement of the roll and means for tilting the roll in said generally parallel plane.

11. Sheet guiding apparatus comprising a roll disposed transversely of the direction of travel of a travelling sheet, means for supporting said roll in rotatable engagement with the sheet, means for tilting said roll about an axis generally perpendicular to the sheet and intersecting the sheet at a point between said roll and the source from which the sheet is drawn, the radius of the arc of tilting of said roll having length within the range of approximately one to one and one half times the width of said sheet, whereby a tilting of said roll carries said sheet, including portions at opposite sides of said roll, in one lateral direction relative to said direction of travel of the sheet, and detector means responsive to any lateral deviation of the sheet from its proper path for initiating a movement of the tilting means in opposition to said deviation.

12. Sheet guiding apparatus for acting on a travelling sheet, comprising a pair of elements from one to the other of which a sheet is to travel, said elements being disposed in spaced general parallelism in a common plane and having extent generally transversely of the direction of sheet travel, detector means arranged and adapted to be actuated when the sheet becomes displaced laterally out of its predetermined proper path, a sheet-engaging roll disposed generally transversely of the direction of sheet travel between said elements, means movably supporting said roll for transverse movements in a plane generally parallel with said common plane of said elements and for tilting of the roll in said generally parallel plane, said supporting means comprising a pair of links disposed outwardly of the opposite edges of said sheet and inclined generally toward each other, the outermost end of each link being pivotally connected to a relatively fixed support and the other end of each link being pivotally connected to the adjacent end of said roll, mechanism responsive to an actuation of said detector means for efiecting a transverse movement of the roll in said generally parallel plane for carrying the engaged travelling sheet transversely of the general direction of travel of the sheet independently of orces transmitted to the roll by the travelling sheet, the said inclined links moving simultaneously with said roll to positions of relatively different inclinations thereby to tilt the transversely moving roll in said generally parallel plane with the direction and magnitude of the tilt conducive to maintenance of the sheet in the position to which it is carried by the said roll.

13. In a sheet guiding apparatus for acting on a travelling sheet which is travelling between two spaced elements disposed in general parallelism in a common plane, a roll disposed generally transversely of the direction of travel of the travelling sheet between said elements, means movably supporting the roll in engagement with the travelling sheet whereby the roll is rotated by the sheet, detector means arranged and adapted to be actuated when the sheet becomes displaced laterally out of its predetermined proper path, means responsive to an actuation of said detector means for moving the roll transversely of the direction of sheet travel and in a plane generally parallel with said common plane of said elements thereby to quickly carry the sheet laterally substantially into its said proper path with portions of the sheet at opposite sides of the roll being carried toward said proper path, and means for tilting the roll in said generally parallel plane thereby to produce a force acting on the sheet in the direction in which it was carried on the roll and of a magnitude approximating the magnitude of forces which may be acting on the sheet in direction tending to move the sheet back out of its said proper path.

References Cited in the file of this patent UNITED STATES PATENTS 593,037 Wetherbee Nov. 2, 1897 1,634,984 Dickhaut July 5, 1927 1,754,629 Kirk Apr. 15, 1930 2,331,030 King Oct. 5, 1943 2,387,036 Morse Oct. 16, 1945 2,630,319 Heilman et al. Mar. 3, 1953 

